/* ============================================================
   Design-System — Projekt LMKD
   Spezifikation Kap. 6 (Gestaltung), 10 (Barrierefreiheit),
   14 (keine Tracking-Cookies), 13 (Datenschutz als Markenkern)
   - Selbstgehostete/Systemschriften (keine externen Font-Dienste)
   - WCAG 2.1 AA Kontraste
   - Dark Mode, prefers-reduced-motion
   ============================================================ */

:root {
  --c-bg: #fafaf7;
  --c-bg-soft: #eef0eb;
  --c-fg: #1b1f24;
  --c-fg-muted: #4a525c;
  --c-accent: #1a5f6b;      /* ruhiges Teal — keine „Big-Tech“-Optik */
  --c-accent-soft: #2f7a88;
  --c-line: #d5d9d3;
  --c-focus: #0b3f48;
  --c-invert-bg: #101418;
  --c-invert-fg: #e8ece9;
  --font-sans: "Noto Sans", "Noto Sans Georgian", system-ui, -apple-system,
               "Segoe UI", Roboto, sans-serif;
  --radius: 8px;
  --space: clamp(16px, 3vw, 40px);
}

/* Dark Mode (Kap. 6.1, umschaltbar im Footer) */
:root[data-theme="dark"] {
  --c-bg: #101418;
  --c-bg-soft: #1a2026;
  --c-fg: #e8ece9;
  --c-fg-muted: #b3bcc4;
  --c-accent: #6fb7c4;
  --c-accent-soft: #8fceda;
  --c-line: #2a323a;
  --c-focus: #8fceda;
  --c-invert-bg: #fafaf7;
  --c-invert-fg: #1b1f24;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--c-fg);
  background: var(--c-bg);
}

/* Skip-Link (A11Y-4) */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--c-focus);
  color: #fff;
  padding: 10px 16px;
  z-index: 100;
}
.skip-link:focus { left: 0; }

/* Декоративный фон (матричный дождь) — позади контента, без pointer-events */
#matrix-bg {
  position: fixed; inset: 0; z-index: 0;
  display: none;               /* включается JS (matrix.js), только при отсутствии reduced-motion */
  width: 100vw; height: 100vh;
  pointer-events: none;
  opacity: 0.45;               /* приглушённо, чтобы не мешать тексту */
}
/* Контент поверх фона */
.site-header, main, .site-footer { position: relative; z-index: 1; }

/* Layout */
.site-header { border-bottom: 1px solid var(--c-line); background: var(--c-bg); }
.header-inner {
  max-width: 1180px; margin: 0 auto; padding: 14px var(--space);
  display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap;
}
.brand { font-weight: 700; color: var(--c-fg); text-decoration: none; font-size: 1.05rem; }

/* Hamburger (nur mobil) */
.nav-toggle {
  display: none; flex-direction: column; gap: 5px; justify-content: center;
  width: 44px; height: 44px; padding: 10px; margin-left: auto;
  background: none; border: 1px solid var(--c-line); border-radius: var(--radius); cursor: pointer;
}
.nav-toggle span { display: block; height: 2px; width: 100%; background: var(--c-fg); border-radius: 2px; transition: transform .2s, opacity .2s; }
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
.nav-toggle:hover { background: var(--c-bg-soft); }

.nav-wrap { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.nav-tools { display: flex; align-items: center; gap: 8px; }
.main-nav { display: flex; gap: 4px; flex-wrap: wrap; }
.main-nav a {
  color: var(--c-fg); text-decoration: none; padding: 8px 12px; border-radius: var(--radius);
}
.main-nav a:hover, .main-nav a:focus-visible { background: var(--c-bg-soft); }
.main-nav a[aria-current="page"] { background: var(--c-bg-soft); font-weight: 600; }

/* Language switcher (I18N-1, J5) */
.lang-switch { display: flex; gap: 2px; border: 1px solid var(--c-line); border-radius: var(--radius); padding: 2px; }
.lang-switch a {
  color: var(--c-fg-muted); text-decoration: none; font-size: 0.8rem; padding: 4px 8px; border-radius: 6px;
}
.lang-switch a[aria-current="true"] { background: var(--c-accent); color: #fff; font-weight: 700; }

.theme-toggle {
  border: 1px solid var(--c-line); background: var(--c-bg); color: var(--c-fg);
  border-radius: var(--radius); padding: 6px 10px; cursor: pointer; font-size: 0.85rem;
}
.theme-toggle:hover { background: var(--c-bg-soft); }

main { max-width: 980px; margin: 0 auto; padding: clamp(24px, 5vw, 64px) var(--space) 80px; }

h1 { font-size: clamp(1.8rem, 4.5vw, 2.6rem); line-height: 1.15; margin: 0 0 16px; }
h2 { font-size: clamp(1.3rem, 3vw, 1.7rem); margin: 2em 0 0.5em; }
h3 { font-size: 1.15rem; margin: 1.5em 0 0.4em; }

.lead { font-size: clamp(1.05rem, 2.5vw, 1.25rem); color: var(--c-fg-muted); margin-bottom: 32px; }

.card {
  border: 1px solid var(--c-line); border-radius: var(--radius); padding: 20px; margin: 14px 0;
  background: var(--c-bg-soft);
}

a { color: var(--c-accent); }
a:focus-visible, button:focus-visible { outline: 3px solid var(--c-focus); outline-offset: 2px; }

/* Buttons */
.btn {
  display: inline-block; background: var(--c-accent); color: #fff;
  padding: 12px 20px; border-radius: var(--radius); text-decoration: none; font-weight: 600;
}
.btn:hover { background: var(--c-accent-soft); }
.btn-sm { padding: 8px 14px; font-size: 0.9rem; }

/* Forms (A11Y-5) — Datensparsamkeit (FF-7) */
form { display: grid; gap: 16px; max-width: 560px; margin-top: 24px; }
label { font-weight: 600; }
input, select, textarea {
  font: inherit; color: var(--c-fg); background: var(--c-bg-soft);
  border: 1px solid var(--c-line); border-radius: var(--radius); padding: 10px 12px; width: 100%;
}
.field-error { color: #b3261e; font-size: 0.9rem; }
.required::after { content: " *"; color: #b3261e; }

/* Footer (Kap. 17.2 I-9, Kap. 6 Dark Mode-Toggle) */
.site-footer { border-top: 1px solid var(--c-line); background: var(--c-bg); font-size: 0.9rem; color: var(--c-fg-muted); }
.footer-inner {
  max-width: 1180px; margin: 0 auto; padding: 24px var(--space);
  display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap;
}
.footer-inner a { color: var(--c-fg-muted); text-decoration: none; }
.footer-inner a:hover { text-decoration: underline; }

/* Simple diagrams / code */
pre { overflow-x: auto; background: var(--c-bg-soft); padding: 16px; border-radius: var(--radius); }
code { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }

/* Architektur-Diagramm (F-2) */
.arch-diagram { margin: 20px 0; }
.arch-diagram svg { display: block; max-width: 100%; height: auto; }
.arch-diagram text { font-family: var(--font-sans); }
:root[data-theme="dark"] .arch-diagram text { fill: #e8ece9; }
:root[data-theme="dark"] .arch-diagram rect[fill="#eef0eb"] { fill: #1a2026; }

/* Accessibility: reduced motion (A11Y-8, Kap. 6.1) */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

/* Responsive (R-1) — mobile First, Hamburger-Menü */
@media (max-width: 900px) {
  .nav-toggle { display: flex; }
  .brand { margin-right: auto; }
  .nav-wrap {
    display: none; width: 100%; order: 3;
    flex-direction: column; align-items: stretch; gap: 12px;
    padding-top: 12px; border-top: 1px solid var(--c-line); margin-top: 6px;
  }
  .site-header.nav-open .nav-wrap { display: flex; }
  .main-nav { flex-direction: column; }
  .main-nav a { padding: 12px 8px; border-radius: var(--radius); }
  .nav-tools { flex-wrap: wrap; justify-content: space-between; }
}